Loud speaking telephone receiver



June 14,1927.

G. J. ZISCH I LOUD SPEAKING TELEPHONE RECEIVER 1924 2 Sheets-Sheet 1 Filed Jan. 25

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Patented June 14, 1927'.

LOUD-SPEAKIN G TELEPHONE REGEIUTER.

Application filed January 23, 1924. Serial No. 687,929.

The recent rapid development of high powered sending and receiving apparatus for radio-telephony has necessitated quite radical changes in the form of the receiver and the methods for the proper adjustment of the parts in order to take care of the increased flux in the magnet system so as to preserve clarity andvolume of sound reception. It is to accomplish these results that the present invention was designed, and it consists in the means employed for adjusting the magnet system within the receiver cup relative to the armature diaphragm, and at the same time provide an improved amplifying diaphragm connected directly to the armature'diaphragm and supported in such a manner as to afford an air chamber of very materially enlarged capacity.

Several embodiments of the improvement are shown in the accompanying drawings, all of which contemplate the same principle of operation, and they are designed solely to meet the different conditions found in actual practice and service.

Fig. 1 is a side elevational view of the improved amplifying receiver, shown as mounted upon a portable stand.

Fig. 2 is a vertical sectional View of the same.

Fig. 3 is a plan view of the receiver cup with the magnet system in place.

Fig. 4 is a bottom plan and Fig. 5 is an edge view of the insulating magnet supporting disk and adjusting spring.

Fig. 6 is a sectional view and Fig. 7 is a front view of a modified form of amplifying diaphragm.

Fig. 8 isa sectional view of a recelver showing the amplifying diaphragm as designed for use with an amplifying horn Fig. 9 is a sectional view of a recelver showing the armature diaphragm as combined with the amplifying diaphragm into a single unitary structure.

The receiver comprises a cup 1, within which a magnet system 2, is adjustably mounted. The magnet system comprises permanent magnets which are made of semicircular laminae, 3, 3, and 4, 4, are arranged in the form of a ring with their like poles clamped against the L-shaped pole pieces 5, 5, upon the disk of insulating material 6 by screws 7, 7, and arc-shaped clamping nuts 8, 8. The usual coils 9, 9 are wound the poles 5, 5., and leads therefrom connected to the insulated posts 10, 10, from which the covered conductor cables 11, 11 are led out through an aperture in the side of the cup 1.

A. headed screw 12 is forced through an aperturev in the center of the disk 6, and passes through an aperture in the bottom of the cup 1, and is provided with a thumb nut13 outside the cup. Between the disk 6 and the bottom of the cup 1 is the star spring 14, centrally apertured for the passage of the'screw 12, and having a broad flat face which bears against the bottom of the cup. The arms 15 are bent so that their ends may bear upon the back of the disk 6, near its margin. In this manner a very firm foundation for the magnet system is formed within the cup, and at the same time, it may be adjusted in or out by means of the thumb nut 13.

The cup 1 has a broad fiat flange 16, against which the armature diaphragm 17 is clamped. The adjusting of the magnet system is such that the extremities of the poles 5, 5, are closely contiguous to the center of the diaphragm 17, but just far enough away that with the maximum amplitude of vibration of the diaphragm there will be no actual contact.

Asa means for amplifying the sound vibrations of the diaphragm 17, an amplifying diaphragm 18 of general spherical shape, is mounted upon a similarly shaped metal support 19 by means of the clamping ring 20 and screws 21. The support 19 is so formed as to leave a thin air chamber 22 between it and the diaphragm 18. The support 19 is clamped against the diaphragm 17 by means of the screws 23 leaving a thin circular air chamber 24 in front of the diaphragm, with a central aperture connecting the two chambers 22 and 24, and through which the spacer 25 connecting the centers of the two diaphragms may pass.

,When connected into a talking telephone circuit, or used as a radio telephone receiver, the sound vibrations, acting through diaphragm 17 are so materially amplified by the diaphragm 18 that they may be heard at a distance without other aids. Moreover, clarity of articulation and absence of distortion are at once apparent.

As a means for supporting the receiver so that the amplifying diaphragm may be directed toward ciftejrent points, there is pr vided a pedestal 26 upon the j brat-ions, and particularly t parto'f which the U-shape'd yoke 27 is ivotally mounted by means of the bolt 28. etween the arms of the yoke 27 the cup 1, of the receiver is supported upon the trunnions 29, so that the whole receiver may be tilted up or down, or turnedsidewise, as may be desired.

In connecting the two diaphragms 17 and 18as above described it sometimes happens that the spacer is just a little too long or too short, resulting in a slight distortion of the diaphragm armature 17. It then becomes necessary to adjust the magnet system so that the poles 5, 5 are in proper relation to the center of the diaphragm armature 17,

by manipulating the thumb nut 13 as above described.

In Fi s. 6 and 7, is shown a slight modification 0 the am Jlifying diaphragm. In this case the entire ace of the diaphra m 18' is made up of a series of annular cori hgations, which serve to make the diaphragm more widely responsive to the whole range of musical notes which are now being transmitted by radio telephony.

The forms above described are admirably adapted for use where a general diffusion or distribution of the sound vibrations is desired. Where, however, it is desired that centrated to a particu ture illustrated in Fig. 8.

In this form the receiver cup 1, armature diaphragm and the magnet system remain the same. The amplifying diaphragm has the spherical shape but its supporting flange 31 is somewhat wider and is provided with an annular corrugation 32, thereby making the body of the diaphragm more readily rcsponsive to the slight flexures impressed upon it by the main diaphragm, the annular support 33 is corres ondingly reduced in size, and provided wit 1 the circular recess 34, and the air chamber 35 at the rear of the diaphragm 30. The diaphragm is clamped to the support 33 by means of the cap 36 and screws 37, the cap being rovidcd with the clearance recess 38 at the ack and the central threaded aperture 39 into which the nipple 40 is screwed. The horn 41 may he slipped over the nipple 40, and servesto concentrate the sound vibrations in any desired direction.

In order to amplify very weak sound viose coming from distant broadcasting stations by the form of receiver shown in Fig. 9, receiver cup, and ma net system remain the same as above de- SCIfiRd except that the poles 5, 5 are made slightly longer so as to protrude a greater distance from their respective coils. The concave support 42 is shaped somewhat like the familiar wash basin, and has a pair of slots 43, 43 ,in the bottom through which the r direction, this is best accomplished by the use of the structwo poles 5, 5. protrude. The diaphragm 44: is made to conform to the shape of the support 42 so as to leave the air chamber therebetween. The-fiat-disk-like center portion 45 of the diaphragm is of magnetic material and'serves the dual purpose of diaphragm and armature. The structure is in e'flectthe combining of the primar diaphragm 17 and the amplifying dia ragm 18 as shown in Fig. 2, into a single iirtegral diaphragm. However, because of the remoteness of its supporting edge or margin from its vibrating center it is very sensitive to weak magneticfluxes in the ma net system, and further, because of the wi e flaring amplifying portion of the diaphragm, those very weak vibrations are so amplified or magnified as to become clearly audible. This form however is not adapted for use where the magnetic fluxes are strong, since the-extreme sensitiveness of the armature part of it would result in actual contactwith the poles 5', 5'.

structures, which lend themselves readily not only to simple manufacturing procemesbut also to simple-manipulation in use.

I claim:

1. In a telephone reeeiver,'the combination of a plane armature diaphragm and a spherically concave secondary diaphragm, a spacing member connecting the centers of said diaphragms, a supporting member located between said diaphragms and forming therewith two connected air chambers of uniform thickness conforming in shape respcctivelywith adjacent faces of said diaphragms.

In a telephone receiver, the combination of a plane armature diaphra m and a. spherically concave amplifying diaphragm, a spacing member connecting the centers of said diaphragms. a supporting member located between and secured to the diaphragms at their respective margins, said supporting member having recesses in its faces which form with said diaphragmstwo connecting air chambers of substantially the same contour audextent as the said diaphragmsl 3. In a telephone receiver, the combination of a receiver cup, a magnet system within said cup, anarmature diaphragm supported upon the margin of. said cup, asap porting member having a shallow circular recess upon its rear side, said member being clamped to the flanged margin of said pu with the margin of said armature diaphragm therebetween, a spherically concave recess upon the front side ofsaid member, and '1 spherically concave amplifying armature se cured at its marginto the margin ofsaid member having recesses in its faces and forming with said diaphragms thin connecting air chambers, and means upon the bottom of said cup for adjusting the poles of said magnet system into close contiguity to said armature diaphragm.

In a telephone receiver, the combination of a primary diaphragm, and a spherically concave amplifying diaphragm, said diaphragm being spaced apart and connected together at their centers, and a recessed member located between said diaphragms and forming therewith two thin connecting air chambers respectively of the same contour and substantially of the same size as said diaphragms.

6. In a telephone receiver, the combination of a plane primary diaphragm, a spherically concave amplifying diaphragm, and a connecting spacer at the centers, a supporting member having a spherical recess upon one face adapted to receive said amplifying diaphragm and form therewith a thin air'chamber and a plane shallow recess upon its other face adapted to form with said primary diaphragm a thin disk like air chamber, and a magnet system for vibrating said diaphragms.

7. In a telephone receiver, the combination of a plane primary diaphragm, and a spherically concave diaphragm connected together at their centers, means for supporting said diaphragms in fixed relation at their marginal edges, said means being formed with shallow recesses in the opposite faces thereof to form with said diaphragms thin connecting air chambers.

8. In a telephone receiver, the combination of a spherically concave diaphragm having a multiplicity of concentric steps therein leading from the base to the apex, means for peripherally supporting said diaphragm, and electro-magnetic means operating at the center of said diaphragm for vibrating the same.

9. In a telephone receiver, the combination of a spherically concave diaphragm having a flat circular marginal flange and a plurality of concentric annular corrugations in the inn-er surface thereof, means for supporting said mar 'inal flange, said means forming with said diaphragm a closed air cham her, and electro-magnetic means operating at the center of said diaphragm for vibrating the same.

10. In telephone receiver, the combination of a flanged receiver cup, a plane armature diaphragm and a spherically concave amplifying diaphragm connected together at their centers, means for supporting said diaphragms from the flange of said cup for vibration, electro-magnetic vibrating means within said cup, and manual means upon said cup for adjusting the poles of said electro-n'iagnetic means toward and away from said armature diaphragm.

11. In a telephone receiver, the combination of a receiver cup, a diaphragm mounted thereon, electro-magnetic means within said cup for vibrating said diaphragm, said means comprising a freely floating insulating disk, a magnet system mounted thereon, a screw threaded stem secured at the center of said disk and projecting through the bottom of said cup, a flat faced star spring upon said stem between said disk and the bottom of said cup, and a threaded thumbnut upon the protruding end of said stein whereby the poles of said magnet system may be adjusted toward and away from the center of said diaphragm.

GEORGE J. ZISCH. 

